U.S. patent number 6,955,689 [Application Number 09/982,299] was granted by the patent office on 2005-10-18 for annuloplasty band and method.
This patent grant is currently assigned to Medtronic, Inc.. Invention is credited to Joseph C. Morrow, Timothy R. Ryan.
United States Patent |
6,955,689 |
Ryan , et al. |
October 18, 2005 |
Annuloplasty band and method
Abstract
An annuloplasty band comprising a sheath, and a generally
arcuate stiffening element disposed within the sheath. The
stiffening element extends from a first end to a second end, and
preferably includes eyelets at its first and second ends adapted to
receive sutures to secure the annuloplasty band to a valve annulus.
The annuloplasty band preferably has a low profile (e.g., a
thickness less than 3 mm). In embodiments intended for mitral valve
repair, the eyelets are particularly adapted to receive sutures to
secure the annuloplasty band to the antero-lateral trigone and
postero-medial trigone. A holder and sizer device useful with the
annuloplasty band are also provided.
Inventors: |
Ryan; Timothy R. (Shorewood,
MN), Morrow; Joseph C. (Eden Prairie, MN) |
Assignee: |
Medtronic, Inc. (Minneapolis,
MN)
|
Family
ID: |
23055501 |
Appl.
No.: |
09/982,299 |
Filed: |
October 16, 2001 |
Current U.S.
Class: |
623/2.36 |
Current CPC
Class: |
A61F
2/2445 (20130101); A61F 2/2448 (20130101); A61F
2/2466 (20130101); A61F 2/2496 (20130101) |
Current International
Class: |
A61F
2/24 (20060101); A61F 002/24 () |
Field of
Search: |
;623/2.36,2.37,2.38,2.39,2.4,2.41,2.42 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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0 257 874 |
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Feb 1988 |
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EP |
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WO 99/04730 |
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Feb 1999 |
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WO |
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WO 99/29269 |
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Jun 1999 |
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WO |
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WO 99/49816 |
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Oct 1999 |
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WO |
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WO 00/23007 |
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Apr 2000 |
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WO |
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WO 00/59408 |
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Oct 2000 |
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WO |
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WO 00/62715 |
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Oct 2000 |
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WO |
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WO 00/74603 |
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Dec 2000 |
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WO |
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WO 00/74604 |
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Dec 2000 |
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WO |
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Other References
US 6,197,052, 03/2001, Cosgrove et al. (withdrawn).
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Primary Examiner: McDermott; Corrine
Assistant Examiner: Matthews; William H
Attorney, Agent or Firm: Berry; Tom Hohenshell; Jeffrey
J.
Parent Case Text
CROSS-REFERENCE TO RELATED APPLICATIONS
This application claims the benefit of, and incorporates by
reference an entirety of, U.S. application Ser. No. 60/276,174,
filed on Mar. 15, 2001.
Claims
What is claimed is:
1. An annuloplasty band for repair of an atrio-ventricular valve
forming a valve annulus, the band comprising: a sheath; and a
generally arcuate stiffening element entirely disposed within the
sheath, the stiffening element extending from a first end to a
second end, wherein each of the first and second ends includes an
eyelet adapted to receive a suture for securing the annuloplasty
band to the valve annulus; wherein upon assembly, a maximum
transverse width of the sheath at the first and second end eyelets
is greater than a maximum transverse width of a remainder of the
sheath.
2. The annuloplasty band of claim 1, wherein the valve is a mitral
valve having an antero-lateral trigone, a posterior leaflet, and a
postero-medial trigone; wherein the arcuate shape of the band
generally conforms to an expected natural shape of the valve
annulus; and further wherein the eyelets are adapted to secure the
annuloplasty band to the intero-lateral trigone and the
postero-medial trigone, respectively, via sutures.
3. The annuloplasty band of claim 1, wherein the valve is a
tricuspid valve having an anterior leaflet, a posterior leaflet and
a septal leaflet, each of the leaflets defined by a base relative
to the valve annulus; wherein the arcuate shape of the band
generally conforms to an expected natural shape of the valve
annulus; and further wherein the eyelets are adapted to secure the
annuloplasty band to the base of the septal leaflet and the base of
the anterior leaflet, respectively, via sutures.
4. The annuloplasty band of claim 1, wherein the stiffening element
includes a wire having opposite ends bent back onto itself to form
the eyelets.
5. The annuloplasty band of claim 4, wherein the wire is overmolded
with an elastomeric material.
6. The annuloplasty band of claim 5, wherein the elastomeric
material includes a material selected from the group consisting of
biocompatible thermal plastic elastomer and silicone.
7. The annuloplasty band of claim 4, wherein the wire is configured
to define a compound curve including an intermediate portion having
a first radius of curvature and opposite end portions each having a
second radius of curvature, wherein the first radius of curvature
is greater than the second radius of curvature.
8. The annuloplasty band of claim 7, wherein each of the end
portions includes: a transition segment extending outwardly from
the intermediate portion, the transition segment having the second
radius of curvature; an end segment extending from the transition
segment, the end segment having a third radius of curvature;
wherein the second radius of curvature is greater than the third
radius of curvature.
9. The annuloplasty band of claim 1, wherein the stiffening element
includes a molded polymeric element.
10. The annuloplasty band of claim 1, wherein the sheath is
discretely marked at a first location corresponding to a position
of the first end eyelet and at a second location corresponding to a
position of the second end eyelet.
11. The annuloplasty band of claim 10, wherein the sheath is marked
to indicate eyelet placement by a suture having a color different
from a color of the sheath.
12. The annuloplasty band of claim 1, wherein the stiffening
element is radio-opaque.
13. The annuloplasty band of claim 1, wherein the sheath is formed
of a fabric material.
14. The annuloplasty band of claim 1, wherein the sheath is formed
of biological tissue.
15. The annuloplasty band of claim 1, wherein the band has a
thickness no greater than approximately 3 mm.
16. The annuloplasty band of claim 1, wherein the stiffening
element is configured to independently maintain a generally arcuate
shape in an X-Y plane and a generally saddle-shape in a Z-plane.
Description
FIELD OF THE INVENTION
This invention relates generally to devices and methods for repair
of heart valves, such as annuloplasty rings and bands, and more
particularly to an annuloplasty band, annuloplasty band holder,
annuloplasty sizer and annuloplasty method.
BACKGROUND OF THE INVENTION
Annuloplasty prostheses, generally categorized as either
annuloplasty rings or annuloplasty bands, are employed in
conjunction with valvular reconstructive surgery to assist in the
correction of heart valve defects such as stenosis and valvular
insufficiency. There are two atrio-ventricular valves in the heart.
That on the left side of the heart known as the mitral valve, and
that on the right side known as the tricuspid valve. Anatomically
speaking, each valve type forms or defines a valve annulus and
valve leaflets. To this end, the mitral and tricuspid valves differ
significantly in anatomy. Whereas the annulus of mitral valve is
somewhat "D" shaped, the annulus of the tricuspid valve is more
nearly circular.
Both valves can be subjected to or incur damage that requires that
the valve(s) be repaired or replaced. The effects of valvular
dysfunction vary. Mitral regurgitation has more severe
physiological consequences to the patient than tricuspid valve
regurgitation, a small amount of which is tolerated quite well.
Many of the defects are associated with dilation of the valve
annulus. This dilation not only prevents competence of the valve
but also results in distortion of the normal shape of the valve
orifice. Remodeling of the annulus is therefore central to most
reconstructive procedures on the mitral valve. In this regard,
clinical experience has shown that repair of the valve, when
technically possible, produces better long-term results as compared
to valve replacement.
Many procedures have been described to correct pathology of the
valve leaflets and their associated chordae tendinae and papillary
muscles. In mitral repairs, it is considered important to preserve
the normal distance between the two fibrous trigones. The trigones
almost straddle the anterior leaflet portion of the annulus.
Between the left and right fibrous trigones the mitral annulus is
absent (as described by Tsakiris A. G. "The physiology of the
mitral valve annulus" in The mitral valve--a pluridisciplinary
approach. ed. Kalmanson D. Publishing Sciences Group, Acton, Mass.
1976, pg 21-26). This portion of the mitral valve apparatus is
formed by the change of the anterior portion of the base of the
aorta into the (so called) sub-aortic curtain, and hence into the
anterior leaflet of the mitral valve. A significant surgical
diminution of the inter-trigonal distance could cause left
ventricular outflow obstruction. Thus, it is highly desirable to
maintain the natural inter-trigonal distance during and following
mitral valve repair surgery.
Consequently, when a mitral valve is repaired (be it the posterior
or anterior leaflet) the result is generally a reduction in the
size of the posterior segment of the mitral valve annulus. As a
part of the mitral valve repair, the involved segment of the
annulus is diminished (i.e. constricted) so that the leaflets may
coapt correctly on closing, or the annulus is stabilized to prevent
post-operative dilatation from occurring. Either is frequently
achieved by the implantation of a prosthetic ring or band in the
supra annular position. The purpose of the ring or band is to
restrict and/or support the annulus to correct and/or prevent
valvular insufficiency. However, it is important not to over
restrict the annulus or an unacceptable valvular stenosis could
result. As described above, in mitral valve repair, constriction of
the mitral annulus should take place only in the area of the
posterior section of the valve annulus.
Shortening of the posterior portion of the mitral valve annulus may
be accomplished in several ways. Firstly, by implanting a
substantially inexpansible ring (smaller in size than the annulus).
With this type of device the surgeon must accurately choose the
size of ring that will just prevent insufficiency, yet will not
cause significant valvular stenosis. Secondly, by using a
contractible ring that may be complicated during implantation. This
type has the disadvantage that the surgeon must then accurately
judge not only the ring size to use, but also how to space the
implanting sutures in the ring and the annulus so that, when
implanted, insufficiency is minimized, yet there will be no
significant valvular stenosis. Thirdly, and preferably, by a
substantially inexpansible ring or band that may be contracted only
in appropriate segments (and not in the anterior portion). The
natural inter-trigonal distance should be maintained, and the
anterior leaflet should not be diminished in circumference.
In tricuspid valve repair, constriction of the annulus usually
takes place in the posterior leaflet segment and in a small portion
of the adjacent anterior leaflet. The septal leaflet segment is not
usually required to be shortened.
As described above, both annuloplasty rings and annuloplasty bands
are available for repair of an atrio-ventricular valve. Examples of
annuloplasty rings are shown in U.S. Pat. Nos. 5,306,296;
5,669,919; 5,716,397 and 6,159,240, the teachings of which are
incorporated herein by reference. See, also, Duran C M G, et al.
Clinical and Hemodynamic Performance of a Totally Flexible
Prosthetic Ring for Atrioventricular Valve Reconstruction, (Annals
of Thoracic Surgery 1976;22(5):458-63); and Duran C M G, Repair of
Anterior Mitral Leaflet Chordal Rupture of Elongation (The
Flip-Over Technique.) (Journal of Cardiac Surgery
1986;1(2):161-66.). A flexible annuloplasty ring has been available
under the trade designation "DURAN.TM." by Medtronic, Inc.,
Fridley, Minn., USA. In general terms, annuloplasty rings
completely encompass both the anterior and posterior portions of
the valve annulus. The posterior portion is often diseased or
dilated and not well supported by heart tissue. The anterior
portion, in contrast, is well supported by surrounding heart
tissue. Thus, it is possible that the annuloplasty ring may overtly
support an otherwise healthy anterior portion, potentially leading
to tissue failure.
Annuloplasty bands, on the other hand, are specifically designed to
primarily encompass only a portion of the valve annulus. For
example, a mitral valve annuloplasty band is typically configured
to encompass only the posterior portion of the mitral valve
annulus, thus promoting natural movement of the anterior portion.
In addition to facilitating natural movement of the healthy portion
of the valve annulus, annuloplasty bands can be implanted more
quickly than annuloplasty rings, as fewer sutures are required.
Examples of annuloplasty bands are shown in U.S. Pat. No. 5,824,066
and PCT International Patent Publication No. WO 00/74603, the
teachings of which are incorporated hereby by reference. While
viable, annuloplasty bands present other concerns. For example, if
the band is only anchored into friable valve annulus tissue, there
is some concern that the band may possibly pivot excessively
relative to the valve annulus. Further, the profile (e.g.,
thickness) of prior annuloplasty bands may theoretically be
sufficiently large so as to restrict or disturb blood flow. Thus, a
need exists for an annuloplasty band adapted to provide reinforced
attachment about the valve annulus, and a holder and a sizer that
facilitate implantation thereof.
SUMMARY OF THE INVENTION
One aspect of the present invention relates to an annuloplasty band
that is readily implanted to repair an atrio-ventricular heart
valve, such as the mitral or tricuspid valve, and which may readily
be secured (e.g., sutured) to the valve annulus tissue, for example
to the antero-lateral and/or postero-medial trigones of a mitral
valve. Another aspect of the present invention relates to methods
of implantation of annuloplasty bands, for example, by suturing
through eyelets adjacent the ends of the band to the valve annulus
tissue. This provides an annuloplasty band that is anchored into
the fibrous tissue of the valve (for example, in one embodiment,
the antero-lateral and postero-medial trigones), which is believed
to provide many of the advantages of annuloplasty rings, without
sacrificing the advantages of an annuloplasty band. To this end,
yet another aspect of the present invention relates to a holder for
selectively maintaining the annuloplasty band during the implant
procedure, the holder adapted to facilitate passage of sutures
through the eyelets. Yet another aspect of the present invention
relates to a sizer adapted to promote accurate evaluation of the
valve annulus via sizer cut-out segments and sizer shape, and thus
selection of an optimally sized annuloplasty band.
In one preferred embodiment, the annuloplasty band of the present
invention comprises a sheath, and a generally arcuate stiffening
element disposed within the sheath. The stiffening element extends
from a first end to a second end, and includes eyelets at its first
and second ends adapted to receive sutures to secure the
annuloplasty band to a valve annulus.
In annuloplasty bands of the present invention intended for mitral
valve repair, the stiffening element is preferably configured such
that after implant, the stiffening element extends from a first end
adjacent the antero-lateral trigone past the posterior leaflet to a
second end adjacent the postero-medial trigone, and the eyelets are
adapted to receive sutures to secure the annuloplasty band to the
antero-lateral trigone and postero-medial trigone. Alternatively,
in annuloplasty bands of the present invention adapted for
tricuspid valve repair, the stiffening element is preferably
configured to correspond with the natural tricuspid valve
anatomy.
Preferably, the stiffening element comprises wire having opposite
ends bent back onto itself to form the eyelets. The wire is
preferably overmolded with an elastomeric material, such as
biocompatible thermoplastic elastomeric or silicone material. The
stiffening element is preferably radio-opaque.
Preferably, the sheath is fabric marked to indicate eyelet
placement. For example, the fabric sheath may be marked to indicate
eyelet placement by a suture of contrasting color to the fabric
sheath.
In a second preferred embodiment of the present invention, the
annuloplasty band generally comprises a sheath, and a generally
arcuate stiffening element disposed within the sheath. The
stiffening element has rounded ends, and the band has a thickness
no greater than about 3 mm, preferably no greater than 2.7 mm, and
most preferably no greater than 2.5 mm. The low profile
annuloplasty band offers less restriction or disturbance to blood
flow through the valve. Hence, the minimal cross-section
annuloplasty band may reduce stenosis and turbulence, and may
minimize the risk of thrombus formation.
In another preferred embodiment of the invention, a method of
implantation of an annuloplasty band along the annulus of an
atrio-ventricular valve to repair the valve generally comprises the
following steps:
(a) Providing an annuloplasty band comprising a sheath and a
generally arcuate stiffening element disposed within the sheath,
the stiffening element extending from a first end to a second end,
the stiffening element including eyelets at its first and second
ends adapted to receive sutures to secure the annuloplasty band to
a valve annulus;
(b) Positioning the annuloplasty band along the valve annulus to
encompass a leaflet of the valve annulus, with the first and second
ends of the stiffening element positioned adjacent desired portions
of the valve annulus; and
(c) Suturing the eyelets to the valve annulus.
In one preferred embodiment, the above-described method relates to
repair of a mitral valve. In this regard, the eyelets are
preferably positioned adjacent the antero-lateral trigone and the
postero-medial trigone, respectively. The eyelets are then
preferably sutured to the valve annulus at the antero-lateral and
postero-medial trigones. In an alternative embodiment, the
above-described method relates to repair of a tricuspid valve. To
this end, the annuloplasty band is positioned to surround the
anterior, posterior and a portion of the septal leaflets of the
tricuspid valve. The eyelets are sutured to the respective bases of
the septal and anterior valve leaflets, adjacent the valve annulus
and on either side of the antero-septal commissure to avoid
impairment with the cardiac conduction system of the heart.
In still another preferred embodiment of the invention, a holder is
provided in combination with an annuloplasty band. The annuloplasty
band is mounted on the holder to help position the annuloplasty
band relative to the valve annulus. The holder includes a
band-retaining plate forming cut-out areas providing clearance
about eyelets formed by the band, thereby promoting placement of
sutures through the eyelets.
Yet another aspect of the present invention relates to a sizer for
evaluating a size the valve annulus implant site and indicating
which of a number of varying sized annuloplasty bands is best
suited for the valve annulus. In a preferred embodiment, a
plurality of differently sized sizers are provided, each
corresponding in size with an annuloplasty band of the present
invention. In this regard, each of the sizers preferably includes
markings that identify a potential location of the corresponding
annuloplasty band's eyelets were the correspondingly sized band
selected for implant. Along these same lines, the sizer delineates
a distance between desirable points of the valve annulus. With
respect to mitral valve repair procedure, the sizer affords a
surgeon the ability to measure an intertrigonal distance and an
area of a leaflet of the valve (e.g., anterior leaflet) in order to
select an annuloplasty band that most closely matches those
parameters.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will be further described with reference to the
drawing wherein corresponding reference characters indicate
corresponding parts throughout the several views of the drawing,
and wherein:
FIG. 1 is a top view of one preferred embodiment annuloplasty band
in accordance with the present invention, with portions peeled
away;
FIG. 2 is a cross-sectional view along lines 2--2 of FIG. 1;
FIG. 3 is a top view of a stiffening element employed in the
annuloplasty band of FIG. 1;
FIG. 4 is an enlarged view of a portion of FIG. 1 illustrating a
mark that is provided to indicate the location of any underlying
eyelet on the annuloplasty band;
FIG. 5 is view similar to FIG. 4 with portions of the fabric sheath
broken away to show the eyelet;
FIG. 6 is a perspective representation of one preferred embodiment
stiffening element relative to the X-Y plane and Z direction;
FIG. 7 is a side view of the stiffening element of FIG. 7 in the
X-Y plane and Z direction, illustrating a saddle-shaped curve in
the Z direction in accordance with one embodiment of the present
invention;
FIG. 8 is an exploded perspective view of an annuloplasty band of
FIG. 1 in combination with a holder in accordance with one
preferred embodiment of the present invention;
FIG. 9 is a perspective view of the combination of FIG. 8,
illustrating a handle of the holder being attached to a
band-retaining plate;
FIG. 10 is a perspective, exploded view illustrating assembly of an
annuloplasty band to a band-retaining plate;
FIG. 11A is a top view of the assembled annuloplasty
band/band-retaining plate;
FIG. 11B is a bottom view of the assembly of FIG. 11A;
FIG. 12 is an exploded view of a sizer/handle device in accordance
with the present invention;
FIG. 13 is a top view of a sizer portion of the device of FIG.
12;
FIG. 14 is a perspective view of the sizer device held near a
mitral valve;
FIG. 15 is a perspective view of the combination of FIGS. 8-11,
illustrating removal of the identifying tag to be added to the
patient's records;
FIG. 16 is perspective view of the combination of FIG. 15 held near
a mitral valve;
FIG. 17 is a perspective view of the combination of FIG. 15
illustrating placing a suture through the annuloplasty band;
FIG. 18 is a cross section through a portion of FIG. 17
illustrating further details of placing a suture through the
annuloplasty band;
FIG. 19 is a top view of the mitral valve illustrating details of
placing sutures into cardiac tissue;
FIG. 20 is a perspective view of the combination of FIG. 15
illustrating bringing the band-retaining plate and annuloplasty
band in proximity with the valve annulus and removing the
annuloplasty band from the band-retaining plate;
FIGS. 21 and 22 are enlarged views of a portion of FIG. 19
illustrating cutting a suture holding the annuloplasty band to the
band-retaining plate;
FIG. 23 is a perspective view of the combination of FIG. 15,
illustrating separating the holder from the annuloplasty band;
FIG. 24 is a top view of the annuloplasty band mounted on the valve
annulus of a mitral valve; and
FIG. 25 is a top view of an alternative embodiment annuloplasty
band in accordance with the present invention.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
As illustrated in the drawings, and in particular FIG. 1, a
preferred embodiment of the annuloplasty band of the invention is
designated in its entirety by the reference numeral 40. The
annuloplasty band 40 is particularly adapted to repair one of the
atrio-ventricular valves, such as the mitral and tricuspid valves.
As a point of reference, the annuloplasty band 40 illustrated in
FIG. 1 is configured for mitral valve annulus repair, it being
understood that other shapes may be incorporated for other valve
annulus anatomies (e.g., tricuspid valve annulus). Thus, the
present invention is not limited to mitral valve annuloplasty.
With additional reference to the cross-sectional view of FIG. 2,
the annuloplasty band 40 generally includes a stiffening element
42, such as stiffening wire, and a fabric sheath 44 enclosing the
stiffening element 42. The preferred stiffening wire 42 is
preferably overmolded with a biocompatible, biostable, implantable,
medical grade elastomeric material 45, such as elastomeric
thermoplastic polymers (e.g., polyurethane) or silicone (e.g.,
liquid silicone rubber (LSR)). Alternatively, the stiffening
element 42 can be covered with a tubing 45, consisting of
biocompatible, biostable, implantable, medical grade elastomeric
material such as elastomeric thermoplastic polymers (e.g.,
polyurethane) or silicone elastomeric.
The stiffening element 42 is a generally arcuate and mounted within
the sheath 44. As shown in FIG. 3, the stiffening element 42
extends from a first end 46 to a second end 48, and includes
eyelets 50 and 52 at its first and second ends 46 and 48.
Preferably, the stiffening element 42 is formed of wire 42 having
opposite ends 46 and 48 bent back onto itself to form the eyelets
50 and 52. Most preferably, the wire 42 consists of a single length
of wire. As used herein, "eyelet" means an opening with
substantially closed perimeter but does not require a specific
shape (e.g., an eyelet can be round, square, rectangular,
trapezoidal, hexagonal, tear-drop, oval, elliptical or any other
suitable shape, although shapes with lower stress concentration and
rounded features are generally preferred). In preferred embodiments
in which the stiffening element 42 is formed of wire, for example,
there will be about 0.5 mm gap along the perimeter of the eyelet
50, 52 due to spring back of the wire after forming the eyelet.
Regardless, as illustrated in FIGS. 4 and 5, the eyelets 50 and 52
are adapted to receive at least one suture 61 to secure the
annuloplasty band 40 to a valve annulus (not shown) of a heart
valve, such as a mitral valve, tricuspid valve, etc.
Preferred shapes of the stiffening element 42 are described in
greater detail below. In general terms, however, the stiffening
element 42 is shaped to match the native or natural shape of the
valve annulus in which the annuloplasty band 40 is to be applied.
Thus, the stiffening element 42 can be generally shaped to mimic
the native natural mitral valve annulus anatomy (i.e., generally
symmetrical horseshoe-like shape) for mitral valve annulus repair;
can be generally shaped to mimic the native natural tricuspid valve
annulus anatomy (i.e., non-symmetrical offset curve); etc.
In one preferred embodiment, and with additional reference to FIGS.
16 and 24, whereby the annuloplasty band 40 is adapted for repair
of a mitral valve 55, the stiffening element 42 is configured to
generally match the natural anatomy of the mitral valve 55. As a
point of reference, the mitral valve 55 anatomy is shown in FIGS.
16 and 24 as including a valve annulus 54, an anterior lateral
trigone 56, a posterior leaflet 58, a postero-medial trigone 60, an
inferior commissure 62, and a superior commissure 64. With this in
mind, the annuloplasty band 40 is configured such that after
implant, the stiffening element 42 extends from the first end 46
adjacent the antero-lateral trigone 56 past the posterior leaflet
58 to the second end 48 adjacent the postero-medial trigone 60.
With this one preferred construction, and as described in greater
detail below, the eyelets 50 and 52 are positioned and adapted to
be secured to the value annulus 54 at the antero-lateral trigone 56
and postero-medial trigone 60. In one more preferred embodiment,
the eyelets 50 and 52 are sufficiently large to encompass both
trigone and adjacent commissure so that the first eyelet 50 can be
positioned and maintained to encompass the inferior commissure 62
at the valve annulus 54, and the second eyelet 52 can be positioned
and maintained to encompass the superior commissure 64 at the value
annulus 54.
With continued reference to one preferred embodiment in which the
stiffening element 42, and thus the annuloplasty band 40, is shaped
in accordance with the natural, native mitral valve anatomy, FIGS.
6 and 7 illustrate the stiffening element 42 as preferably being
generally arcuate in an X-Y plane (e.g., C-shaped), and generally
saddle-shaped in the Z direction. This configuration generally
conforms with the expected natural shape of the mitral valve
annulus 54. With this one preferred configuration, the stiffening
element 42 forms a compound curve in the X-Y plane (see, e.g., FIG.
3) including (a) an intermediate portion 66 having a first radius
of curvature R-1, and (b) opposite end portions 68 having a second
radius of curvature R-2, with the first radius of curvature R-1
being greater than the second radius of curvature R-2. Most
preferably, the opposite end portions 68 each include (i) a
transition segment 70 extending outwardly from the intermediate
portion 66, with the transition segment 70 having the second radius
of curvature R-2 in the X-Y plane; and (ii) an end segment 72
extending from the transition segment 70, the end segment 72 having
a third radius of curvature R-3 in the X-Y plane. In this one
preferred embodiment for mitral valve repair, the first radius of
curvature R-1 is greater than the second radius of curvature R-2,
and the second radius of curvature R-2 is greater than the third
radius of curvature R-3. The preferred magnitude of each radius
R-1, R-2 and R-3 will vary within this constraint depending on the
size of the mitral valve being repaired. Alternatively, the
stiffening element 42 can assume other shapes appropriate for
mitral valve annulus repair. Even further, the stiffening element
42 can assume an entirely different shape, that may or may not
include a saddle-shape component, that corresponds with the native
tricuspid valve anatomy.
In addition to the above shape characteristics, the stiffening
element 42 is also preferably radio-opaque so that it may readily
be visualized after implantation. Metal wire, for example, is
radio-opaque. The wire eyelets 50 and 52 provide further definition
in radiographic images (e.g., X-ray photographs, CAT-scans, etc.)
of the annuloplasty band 40 after implantation.
Alternatively, the stiffening element 42 may comprise (e.g.,
consist essentially of) a molded polymeric element. In this
alternative embodiment, the molded polymeric element preferably
includes a radio-opaque filler such as, but not limited to, barium
sulfate. The eyelets 50, 52 could be integrally molded with the
rest of the stiffening element. (As used herein, "integrally
molded" means molded as a single continuous part as opposed to
separate parts mechanically fastened, welded, glued or adhered
together.)
The wire 42 may be formed of any medically acceptable implantable
biocompatible metal, such as MP35N alloy, Elgiloy.TM. Co--Cr--Ni
alloy wire (American Gage & Machine Company, Elgin Ill., USA),
Haynes.TM. alloy (Haynes International, Inc., Kokomo, Ind., USA),
titanium, stainless steel, shape memory materials such as
NITINOL.TM., or other similar inert biocompatible metal. For
example, suitable wire is the wrought cobalt-35 nickel-20
chromium-10 molybdenum alloy identified as "MP35N" (available from
Carpenter Technology Corporation, Wyomissing, Pa., USA). See also
ASTM Specification "F562-00 Standard Specification for Wrought
Cobalt-35 Nickel-20 Chromium-10 Molybdenum Alloy for Surgical
Implant Applications" (American Society For Testing And Materials,
West Conshohocken, Pa., USA.)
Returning to FIG. 1, the fabric sheath 44 is preferably marked to
indicate placement or location of the eyelets 50, 52 otherwise
encompassed by the sheath 44. For example, the fabric sheath 44 may
be marked to indicate eyelet placement by a suture 74 of
contrasting color to the fabric sheath 44. The suture 74 most
preferably forms an "X" in the fabric overlying the eyelet 50 or
52. Alternatively, the sheath 44 may be marked by any biocompatible
marking that indicates the position of the respective eyelet 50 or
52.
Preferably, the fabric sheath 44 comprises a knitted polyester
(e.g., Dacron.TM.) fabric, although woven, nonwoven (e.g.,
spun-bond, melt-blown, staple fiber matrix, etc.) or braided
fabrics are also contemplated, as well as sheaths formed of
harvested biological tissue (e.g., pericardial tissue). The fabric
sheath 44 may optionally be provided with any of various
biocompatible coatings. Most preferably, a longitudinal seam 76 is
formed along the fabric sheath 44 and is oriented toward the
underside of annuloplasty band 40 in use (see, e.g., FIG. 11B) so
that the seam 76 lies against valve tissue and out of the blood
flow path upon implant.
The stiffening element (e.g., wire or molded element) 42
constitutes a preferred embodiment of generally arcuate stiffening
means, mounted within the sheath 44, for resiliently stiffening the
fabric sheath 44. The eyelets 50 and 52 constitute one preferred
embodiment of eyelet means, at the first and second ends of the
stiffening means, for receiving sutures to secure the annuloplasty
band 40 to the valve tissue. A preferred embodiment of the
indicating means for indicating where to place a suture so that the
suture goes through the eyelets is the suture of contrasting color
to the fabric sheath sewn into the fabric sheath. Two preferred
embodiments of the means for providing radio-opaque contrast
include (1) forming the stiffening element 42 of metal wire, or (2)
providing a radio-opaque filler in a molded polymeric stiffening
element. Regardless, construction of the annuloplasty band 40
preferably provides a low profile attribute. More particularly, the
annuloplasty band 40 preferably has a maximum cross-sectional
thickness of no greater than about 3 mm, more preferably no greater
than about 2.7 mm, most preferably no greater than about 2.5
mm.
A preferred embodiment of a holder for use with the annuloplasty
band 40 is illustrated in FIG. 8, and designated in its entirety by
the reference numeral 100. The holder 100 comprises an elongate
handle 102 and a band-retaining plate 104 selectively mounted on
the handle 102. The band-retaining plate 104 of the holder 100 is
adapted to retain the annuloplasty band 40 during implantation of
the annuloplasty band 40. Thus, in accordance with the one
embodiment illustrated in the Figures in which the annuloplasty
band 40 is shaped for mitral valve repair, the general perimeter
shape of the band-retaining plate 104 corresponds generally with a
shape of the mitral valve annulus (an example of which is
designated at 54 in FIG. 16). Alternatively, of course, a perimeter
shape of the band-retaining plate 104 can vary from that shown, and
can instead corresponding generally with a shape of an
alternatively configured annuloplasty band 40 (e.g., a tricuspid
valve annuloplasty band). Regardless, the band-retaining plate 104
includes cut-out areas 106 adapted to overlap the eyelets 50, of
the annuloplasty band 40 otherwise secured to the plate 104 to
guide the placement of implanting sutures through the eyelet 50,
52, as described below. Most preferably, the band-retaining plate
104 is formed of transparent biocompatible thermoplastic or
synthetic resin material, such as polycarbonate or polysulfone.
The handle 102 may be of metal, such as an anodized aluminum alloy
or stainless steel, or a suitable thermoplastic, thermoset or
synthetic resin material. An outer surface of the handle 102 may be
knurled to provide a non-slip finish.
The handle 102 of the holder 100 may be, for example, designed for
a snap-fit engagement in the band-retaining plate 104 as
illustrated in FIG. 9. Most preferably, the snap-fit engagement is
provided by a plurality (e.g., two) of cantilever spring fingers
103 that are received in a slot 105 in the band-retaining plate
104. This snap-fit mechanism allows the handle 102 to be attached
to the band-retaining plate 104 by the surgical staff.
Alternatively, any suitable temporary or permanent means for
attaching the handle 102 and band-retaining plate 104 may be
employed, such as, without limitation, threaded means,
bayonet-mounting means, interference fit, detent lock, welding,
adhesive, insert molding or integrally molding the handle and
band-retaining plate.
The annuloplasty band 40 is mounted on the holder 100 to maintain
the annuloplasty band 40. Preferably, the annuloplasty band 40 is
mounted onto band-retaining plate 104 of the holder 100 at time of
manufacture, and the assembly (or combination) is provided as a
sterile unit. In one preferred embodiment, and as illustrated in
FIG. 10, the band-retaining plate 104 is adapted to receive a
drawstring or suture 108 that is otherwise employed to secure the
annuloplasty band 40 to the band-retaining plate 104. More
particularly, the band-retaining plate 104 forms a plurality of
spaced passage pairs 110a-110f. Each passage pair 110a-110f
includes two holes 112 (best illustrated in FIG. 10 for the passage
pair 110b) extending transversely through the band-retaining plate
104. Each of the holes 112 is adapted to allow passage of the
drawstring suture 108. Further, the holes 112 comprising any one of
the passage pairs 110a-110f are separated by a section of the
band-retaining plate 104. That is to say, each of the passage pairs
110a-110f includes two distinct holes 112, and is not a continuous
slot. With this configuration, the drawstring suture 108 can be
threaded around, and thus engaged by, the band retaining plate 104
as shown. In one preferred embodiment, the passage pairs 110b and
110e further include two fingers 114 projecting from an upper
surface 116 of the band-retaining plate 104. The fingers 114 are
positioned between the respective holes 112, and are spaced from
one another to define a slot 118. Further, each of the fingers 114
forms a channel 120 for receiving the drawstring suture 108. With
this configuration, and as described in greater detail below, the
fingers 114 raise the drawstring suture 108 away from the upper
surface 116, and provide a space (i.e., the slot 118) for severing
the drawstring suture 108.
With the above-preferred embodiment in mind, the annuloplasty band
40 is secured to the band-retaining plate 104 by threading the
drawstring suture 108 through the passage pairs 110a-110f and the
annuloplasty band 104 as shown in FIG. 10. Preferably, a single
drawstring suture 108 is extended from the first passage pair 110a
(and forming a knot 122a) downwardly and sewn to the annuloplasty
band 40; upwardly from the annuloplasty band 40 to the second
passage pair 110b and around the respective fingers 114; downwardly
from the second passage pair 110b and sewn to the annuloplasty band
40; upwardly from the annuloplasty band 40 to the third passage
pair 110c; around the third passage pair 110c, and below the
band-retaining plate 104; upwardly to the fourth passage pair 110d
and wrapped around the fourth passage pair 110d; downwardly from
the fourth passage pair 110d and sewn to the annuloplasty band 40;
upwardly from the annuloplasty band 40 to the fifth passage pair
110e and around the respective fingers; downwardly from the fifth
passage pair 110e and sewn to the annuloplasty band 40; upwardly
from the annuloplasty band 40 and around the sixth passage pair
110d; finally terminating in a knot 122b. Notably, extension of the
drawstring 108 between the third and fourth passage pairs 10c, 10d
(and below the band-retaining plate 104) is preferably sufficient
to form a loop 124 that is defined by a knot 126. The loop 124 can
subsequently be severed from a remainder of the drawstring suture
108. This preferred configuration assists in tightening the
annuloplasty band 40 to the band-retaining plate 104. The
drawstring suture 108 is preferably tied to the band-retaining
plate 104 in such a manner that following severing (via the slots
118 formed by the respective fingers 114), each severed length of
the suture 108 remains connected to the band-retaining plate 104.
Notably, directional terminology, such as "upper," "upwardly,"
"downwardly," "below," etc., are used for purposes of illustration
and with reference to the orientation of FIG. 10. The annuloplasty
band 40 and/or the band-retaining plate 104 can be positioned at a
wide variety of other orientations, such that the directional
terminology is in no way limiting.
The above-described mounting technique is but one available
technique for securing the annuloplasty band 40 to the
band-retaining plate 104. Preferably, however the various points at
which the drawstring suture 108 is sewn to the annuloplasty band 40
are discrete and are spaced from one another. Final assembly of the
annuloplasty band 40 to the band-retaining plate 104 is illustrated
in FIGS. 11A and 11B. As depicted by the top view of FIG. 11A, the
cut-out 106 provide clearance about the eyelets 50, 52 (hidden in
FIG. 11A, but readily identified by the markings 74 on the sheath
44). Further, the drawstring suture 108 is easily severed via the
slots 118 provided by the fingers 114. With respect to the bottom
view of FIG. 11B, the annuloplasty band 40 is effectively mounted
to a bottom surface 128 of the band-retaining plate 104. In one
preferred embodiment, the bottom surface 128 further forms spaced
tabs 130, 132, and 134 that serve to generally support a shape of
the annuloplasty band 40 upon final assembly to the band-retaining
plate 104. The tabs 130-134 preferably do not form grooves or other
side wall curvatures for receiving the annuloplasty band 40, and
preferably do not follow a circumferential profile of the
annuloplasty band 40. Instead, the tabs 130-134 preferably extend
in a perpendicular fashion relative to a plane of the bottom
surface 128 and are tangent to the annuloplasty band 40 profile at
three points, thereby promoting ease of manufacture of the
band-retaining plate 104.
As previously described, alternative configurations/techniques can
be employed for selectively mounting the annuloplasty band 40 to
the band-retaining plate 104. To this end, the band-retaining plate
104 can be configured to maintain the annuloplasty band 40 in a
manner that does not require the drawstring suture 108. For
example, in one alternative embodiment, the tabs 130-134 are
modified to each form a rib (or radially outward projection)
opposite the bottom surface 128. Taken in combination, these ribs
define a radius of curvature that is slightly greater than that
defined by the annuloplasty band 40. With this configuration,
assembly of the annuloplasty band 40 would entail first expanding
the annuloplasty band 40 (i.e., forcing the ends 46, 48 away from
one another) so that the annuloplasty band 40 could be placed over
the ribs. Once properly positioned, the expansion force on the
annuloplasty band 40 is released, allowing the annuloplasty band 40
to contact the tabs 130-134 such that the annuloplasty band 40 is
retained by the tabs 130-134 between the ribs and the bottom
surface 128. Following implant to a valve annulus, the annuloplasty
band 40 is released from the band-retaining plate 104 by simply
pulling the band-retaining plate 104 away from the annuloplasty
band 40 via maneuvering.
An additional component useful as part of an implantation procedure
for the annuloplasty band 40 is a sizer device 150 shown in FIG.
12. The device 150 includes a handle 152 and a sizer 154. The
handle 150 is preferably similar, more preferably identical, with
the handle 102 (FIG. 9) associated with the holder 100 (FIG. 9)
previously described. In other words, the handle 102 used with the
holder 100 is preferably also used with the sizer device 150,
although a different handle can also be employed.
Regardless, the sizer 154 is preferably configured to be
selectively assembled to the handle 152, and, with additional
reference to FIG. 13, provides a perimeter 156 corresponding
generally with a shape of the annuloplasty band 40 (FIG. 1). As
such, the perimeter 156 defines a shape corresponding generally
with the valve annulus to be repaired (e.g., mitral valve,
tricuspid valve, etc.). In the one preferred embodiment, the sizer
154 is configured for evaluating a mitral valve, it being
understood that a tricuspid valve sizer in accordance with the
present invention will define a perimeter corresponding with a
natural shape of a tricuspid valve annulus (not shown).
With respect to the one preferred mitral valve sizer 154, the
perimeter 156 includes a leading segment 158, a trailing segment
160, and opposing cut-out segments 162. The leading segment 158
extends between the opposing cut-out segments 162, and is
preferably curved, mimicking the natural shape of the mitral valve
annulus anatomy. The opposing cut-out segments 162 are located at
approximate positions (relative to the leading segment 158) of the
naturally occurring antero-lateral trigone and the postero-medial
trigone, respectively. Thus, and as described in greater detail
below, when placed next to a valve annulus requiring repair (e.g.,
mitral valve, tricuspid valve, etc.), the sizer 154, and in
particular, the opposing cut-out segment 162, afford a surgeon the
ability to relatively accurately estimate an intertrigonal distance
and related leaflet area. To this end, the sizer 154 preferably
further includes indicia 164 that highlights a location of the
opposing cut-out segment 162 to the surgeon during use. In another
preferred embodiment in which the sizer 154 is configured to
evaluate a tricuspid valve, the leading segment 158 will be
generally shaped in accordance with a shape of a natural tricuspid
valve annulus in a region of at least the posterior tricuspid valve
leaflet. Further, the opposing cut-out segments 162 would be
positioned (relative to the leading segment 158) at the approximate
locations of the septal and anterior tricuspid valve leaflets
(relative to the naturally occurring tricuspid valve annulus).
Regardless of whether the sizer 154 is configured for mitral or
tricuspid valve evaluation, a plurality of differently sized, but
similarly shaped, sizers are preferably provided. Each of the
differently sized sizers 154 would preferably correspond with an
available annuloplasty band 40 (FIG. 1). During use, then, the
surgeon would evaluate the valve annulus to be repaired with
several of the differently sized sizers 154 (on an individual
basis). Once the sizer 154 most closely corresponding with the
valve anatomy is identified, the annuloplasty band 40 corresponding
with that sizer would then be selected for implant.
Operation
The annuloplasty band 40, holder 100, and sizer assembly 150 of the
present invention may be employed in the repair of various heart
valves, particularly the atrio-ventricular valves. One particularly
advantageous application of the annuloplasty band 40 is for repair
of the mitral valve. Regardless of the exact type of valve being
repaired, however, the general method of use is the same. For ease
of illustration, the following example (including illustrations) is
specific to repair of a mitral valve. It should be understood,
however, that a tricuspid valve can similarly be repaired via an
annuloplasty band 40 of the present invention shaped to generally
match the native, natural tricuspid valve anatomy.
Beginning with FIG. 14, the mitral valve 55 is accessed using known
surgical techniques. The sizer device 150 is then directed toward
the valve annulus 54. In particular, the sizer 154 is then directed
toward the valve annulus 54, with the opposing cut-out segments 162
positioned as close as possible the antero-lateral trigone 56 and
the postero-medial trigone 60, respectively. Once positioned, the
surgeon can evaluate an intertrigonal distance and an area of the
anterior leaflet (referenced generally at 170). Based upon this
evaluation, the surgeon can select an appropriately-sized
annuloplasty band 40 (FIG. 1). Alternatively, or in addition, where
the sizer 154 utilized does not closely match the value annulus 54,
a second, differently sized sizer (not shown) can subsequently be
used to again evaluate the valve annulus 54.
With the desired annuloplasty band size in mind, the selected
annuloplasty band 40 is then assembled to the holder 100, as shown
in FIG. 15. In a preferred embodiment, the annuloplasty band 40 is
provided to the surgeon pre-assembled to the band-retaining plate
104, as previously described. With this embodiment, the handle 102
is then attached to the band-retaining plate 104 by the surgical
staff. Where necessary, a thread 180 otherwise connecting an
identification tag 182 to the annuloplasty band 40 may be severed
so that the annuloplasty band 40 is ready for implant.
The annuloplasty band 40 is then directed to the implant site via
maneuvering of the handle 102, as shown in FIG. 16. With respect to
the one exemplary embodiment in which the annuloplasty band 40 is
employed to repair the mitral valve 55, the annuloplasty band 40 is
guided toward the valve annulus 54 and oriented to surround, more
preferably centered relative to, the posterior leaflet 58. The
cut-out areas 106 of the band-retaining plate 104 (and thus the
eyelets 50, 52 (FIG. 1)) are oriented to be adjacent the
antero-lateral trigone 56 and the postero-medial trigone 60,
respectively. Notably, the band-retaining plate 104/annuloplasty
band 40 are slightly spaced from the valve annulus 54 a sufficient
distance to allow suturing of the annuloplasty band 40 to the valve
annulus 54.
With reference to FIGS. 17-19, the annuloplasty band 40 is
connected to the valve annulus 54 with implanting sutures 61. The
implanting sutures 61 are spaced along a relevant portion of the
valve annulus 54 (as is shown in FIG. 19), and pass through the
sheath 44 (as best shown in FIG. 18). Regardless of an exact
spacing, respective ones of the implanting sutures 61 are stitched
through the eyelets 50, 52 as best shown by the enlarged view of
FIG. 5. To this end, the markings 74 (FIG. 4) visually indicate
eyelet location to the surgeon, and the cut-out areas 106 provide
sufficient clearance for passage of the sutures 61. The implanting
sutures 61 otherwise passed through the eyelets 50, 52 are secured
to tissue of the valve annulus 54. In one preferred embodiment, the
implanting suture(s) 61 associated with the eyelet 50 are sewn to
the antero-lateral trigone 56, whereas the implanting suture(s) 61
associated with the eyelet 52 are sewn to the postero-medial
trigone 60.
At this point, the implanting sutures 61 extend between the
annuloplasty band 40 and the valve annulus 54 as a "suture bundle."
Using the handle 102, the annuloplasty band 40 is pushed down the
suture bundle while simultaneously tensioning the implanting
sutures 61 so that the annuloplasty band 40 lies close to the valve
annulus 54. This relationship is shown in FIG. 20. The drawstring
sutures 108 connected to the band-retaining plate 104 are cut at
the passage pairs 110b, 110e (FIGS. 21, 22), releasing the
drawstrings suture 108, and the holder 100 is removed (see, e.g.,
FIG. 23). The implanting sutures 61 are then tightened and tied as
shown in FIG. 24.
Upon completion of the implantation procedure, the annuloplasty
band 40 is fastened to the valve annulus 54 by the implanting
sutures 61. In this regard, the opposing ends of the annuloplasty
band 40 are securely connected to the valve annulus 54 via the
eyelets 50, 52 (FIG. 3). In a more preferred embodiment, the
eyelets 50, 52 are sutured to the antero-lateral and postero-medial
trigones 56, 60, respectively, thereby providing a reinforced
connection that greatly minimizes the possibility of undesirable
movement or pivoting of the annuloplasty band 40 relative to the
annulus valve 54 during subsequent cardiac cycling.
Though not illustrated, implantation of an appropriately shaped
annuloplasty band 40 to a tricuspid valve annulus entails a
procedure highly similar to that described above. The annuloplasty
band 40 is initially presented to the tricuspid valve while
connected to the band-retaining plate (a mitral version of which is
shown at 104 in FIG. 9), and then sutured to the tricuspid valve
annulus tissue.
Once again, sutures 61 are passed through the eyelets 50, 52 (FIG.
3) and sewn to the tricuspid valve tissue to ensure a rigid
connection. In one preferred embodiment, the annuloplasty band 40
shaped for tricuspid valve repair is oriented such that it
surrounds the anterior, the posterior and a portion of the septal
tricuspid valve leaflets, with the eyelets 50, 52 positioned
adjacent to, and sutured to, the bases of the septal and anterior
tricuspid valve leaflets on either side of the antero-septal
commissure. With this one preferred implant positioning, the
annuloplasty band 40 avoids impairment of the cardiac conduction
system of the patient's heart.
Regardless of the valve being repaired, the annuloplasty band 40 is
preferably had a low profile (e.g., maximum cross-sectional
thickness no greater than about 3 mm, more preferably no greater
than about 2.7 mm, most preferably no greater than about 2.5 mm).
With this preferred low profile, the annuloplasty band 40 has
surprisingly been found to reduce the potential for stenosis and
turbulence within the valve, as well as onset of thrombus by
minimizing the restriction or disturbance of blood flow through the
valve.
As various changes could be made in the above constructions and
methods without departing from the scope of the invention as
defined in the claims, it is intended that all matter contained in
the description or shown in the accompanying drawings be
interpreted as illustrative and not in a limiting sense. For
example, while the annuloplasty band 40 has been preferably
illustrated as being an incomplete ring, a continuous structure can
instead be provided. For example, FIG. 25 depicts an alternative
embodiment annuloplasty band 200 including the stiffening element
42 (shown partially in FIG. 25) disposed within a fabric sheath
202. The stiffening element 42 is identical to that previously
described (e.g., FIG. 1), and forms the eyelets 50, 52 (FIG. 3).
The fabric sheath 202 is constructed of a similar material to that
previously described. However, the sheath 202 extends beyond the
eyelets 50, 52, forming a continuous ring. The additional sheath
202 material 204 is available for anchoring to the valve annulus
(e.g., for mitral valve repair, the additional material 204 can be
anchored to the anterior portion of the mitral valve annulus). With
this alternative embodiment, the annuloplasty band 200 provides a
high degree of flexibility at one side of the valve annulus (e.g.,
the anterior portion for a mitral valve application) via the
additional sheath material 204 (i.e., without the stiffening
element 42), and semi-flexibility at the other side (e.g., the
posterior portion for a mitral valve application) via the
stiffening element 42).
* * * * *